Refrigerating apparatus



28, 1930. E. R. I. :PRATT I 1,779,553

- REFRIGERATING APPARATUS Filed' Aug. 5, 1925 Patented Oct. 28, 1930 UNITED STATES PATENT OFFICE ERNEST R. I. PRATT, OF DAYTON, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, TO FRIGIDAIRE CORPORATION, A CORPORATION OF DELAWARE REFBIGERAT'ING APPARATUS Application filed August 5, 1925- Serial No. 48,289.

The present invention relates to refrigerating systems of an absorption type in which a liquid absorbent contain'inga refrigerant is intermittently heated to vaporize the refrigerant which vaporized refrigerant is cooled and condensed and in which the absorbent is intermittently cooled to thus cause vaporization of the refrigerant. The present invention is of the type in which there is provided a conduit conducting refrigerant which is vaporized in a generator to an evaporator which conductor is connected with the generator above the absorbent level therein. This system also includes a second conduit for conducting refrigerant from the evaporator to the generator, which conductor terminates below the level of absorbent within the generator, whereby vaporized refrigerant is readily absorbed by the absorbent.

One of the objects of the present invention is to control the direction of flow of the refrigerant through these conduits in a simple and efficient manner. I

In this type of refrigerating system, there a tendency for the absorbent to be carried with the refrigerant from the generator to the evaporator. Another object of the invention to provide for automatically returning absorbent from the evaporator to the generator.

Another object of the invention is to provide a compact structure. One manner of carrying out this object is to provide a system including such apparatus that the parts there- II of can be placed in juxtaposition and requiring only short interconnecting conduits.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of embodiment of the present invention is clearly shown.

The drawing is a diagrammatic view of an absorption system, the arrangement and the location of the elements composing this system being located as shown merely for the sake of simplicity and clearness.

Referring to the drawings, there is shown a generator-absorber containing an absorbent 21. The outlet for refrigerant from the generator-absorber 20 is connected with an air-cooled dehydrator including parallel ar ranged coils 22 and 23. These coils are connected by a pipe 24 witha pipe 25 through a valve 26. Pipe 25 is connected with a condenser 28 contained within a water tank 29 and the condenser is connected by pipe 30 with an evaporator 31. When the absorbent 21 is heated, refrigerant is vaporized and the vaporized refrigerant collected within the upper portion of the generator-absorber will flow through the above circuit. The absorbent is condensed by dehydrator 22 and flows back into the generator-absorber 20. The vaporized refrigerant will pass through the valve 26 and pipe 25 and will be condensed within the condenser 28 whence it flows into the evaporator 31. When the absorbent 21 is no longer being heated but is being cooled, this cooling will cause a contraction within the system to cause refrigerant to vaporize within the evaporator 31 and flow backthrough pipe 30, condenser 28, pipe 25, to a pipe 33 which is connected with a pipe 34 through a valve 35. The end of pipe 34 is immersed in the absorbent 21 and is provided with a plurality of orifices 36 through which the refrigerant passes. The vaporized refrigerant which is emitted from the orifices 36 will be absorbed'by the absorbent 21.

Referring more in detail the valve 26 includes an inlet chamber 38 and an outlet chamber 39. Chamber 39 is located below chamber 38 and contains a quantity of mercury 40 or any other suitable liquid. A pipe 4-1 extends from the chamber 38 to chamber 39 and has its outlet end immersed in the mercury 40. The pipe 25 is connected with the chamber 39 above the fiuid level therein. Fluid passing from the generator-absorber, flows into thechamber 38 and passes downwardly through a pipe 41 forcing the mercury out of said pipe and escapes within the mercury and bubbles therethrough to chamber 39 whence it passes through pipe 25.

The valve 35 is'constructed similar to valve 26 and includes an upper chamber 48 and lower chamber 49 containing a quantity of mercury 50 and an interconnecting pipe 51 leading from the chamber 48 and immerging within the mercury 50. The refrigerant passing from the evaporator to the generatorabsorber will flow from pipe 33 into chamber 48 through pipe 51. mercury 50, and into pipe 34. Valves 26 and 35 function as nonreturn valves in their respective conduits. If there is a lower pressure within the generator-ahsorber 20 than within the evaporator 31, the refrigerant cannot pass from pipe 25 through the valve 26 to the generator-absorber 20 because pressure within the chamber 39 will merely cause the mercury 40 to raise to a higher level within the pipe 41 but will not permit the escape of gas therethrough in this direction. While at the same time, when the pressure within the evapora tor 31 in higher than the pressure within the generator-absorber, likewise there will be higher pressure in pipe 25 than within the pipe 34 and chamber 49 of the valve 35. lVhen this differential of pressure is present, refrigerant can pass through the valve 35, as previously described, and into the pipe 34. Valve 35 also functions as a non-return valve preventing the flow of refrigerant or absorbent from the pipe 34 to the pipe 25. If there is a higher pressure within the pipe 34 than the pressure within the pipe 25, the mercury will merely rise within the pipe 51 and the mercury within the chamber 49 will prevent the flow of refrigerant therethrough.

Since vaporized refrigerant is more readily absorbed by the absorbent 21 when the refrigerant enters the evaporator below the level of absorbent as by pipe 34 than when it enters the generator-absorber 20 above the level of absorbent therein, the valve 26 or the like is necessary to prevent the return flow of the refrigerant to the generator-absorber above the surface of the liquid therein. The valve 26 offers resistance to flow tending to make the refrigerant flow out the pipe 34. In order to adapt the system to a refrigerator cabinet in which the generator-alisorber is located above the cooling compartment containing the evaporator, it is necessary to use the valve 35 to prevent siphoning of the liquid from the generator-absorber to the evaporator. If no valve were provided between the pipe 34 and pipe 25, refrigerant and absorbent would flow through the pipe 34 into the evaporator; and, after this pipe was filled with absorbent and refrigerant, the absorbent and refrigerant would siphon from the generator-absorber into the evaporator thus defeating the purpose of one phase of the refrigerating cycle. Therefore the valve 35 is connected between pipe 34 and pipe 25 to prevent flow of refrigerant from the generator-absorber through pipe 51 into the chamber 48. Furthermore if no valve 35 were provided, the pipe 34 would need to be long enough vertically so that the weight of liquid therein would prevent the liquid rismg to pipe 25. By using a head of mercury in the valve 35 only a short pipe 34 is necessary. thus providing a compact system.

The mechanism for heating the absorbent includes a. gas burner 53 located below the generator-absorber 20 and the flow of gas from a pipe 54 is controlled by a valve 55. A gas valve lever 56 carries a water receptacle 57, which, when containing water, will lie in the position shown in the drawing in which position the lever 56 is in such a position as to provide for the flow of gas from the pipe 54 to the burner 53, but when no water is present within the receptacle 57 the receptacle and lever 56 will rock to such a position so as to close the valve 55.

The mechanism for cooling the generatorabsorber 20 includes a water coil 60 which is connected with a drain pipe 61 and receives water from a receptacle 62. The receptacle 62 is provided with two compartments 63 and 64. The compartment 63 is connected with the coil 60 and the compartment 64 is connected with the pipe 65 which delivers water to the receptacle 57. \Vater is conducted to the receptacle 62 by pipe 67 connected with the condenser water tank 29. Water is delivered to the tank 29 through a pipe 68 and is connected with a valve 69 which is controlled by a float 70 for maintaining a predetermined quantity of water within the tank 29. The flow of water to the compartments 63 and 64 is intermittent so that when water is being delivered to the water receptacle 57 for maintaining the gas valve open, no water will flow through the water coil 60 and vice versa, and when water is flowing through the Water coil 60 no water will flow into the water receptacle 57 and consequently the valve 55 will be closed so that no gas will flow to the burner 53.

The mechanism for controlling the flow of water from the pipe 67 to either of com artments 63 and 64, includes a bafile 78, w ich, when in full line position as shown in the drawing, will permit the flow of water from the pipe 67 to the compartment 64; and, when the baflie 78 is in the dotted line position 7 8, it will battle the water and cause it to flow into the compartment 63. Baffle 78 is controlled by a trip mechanism 71 which in turn is controlled b a controller 72 including a metallic bellows 3 connected by a pipe 74 with a thermostatic tube 75. This tube is responsive to the temperature of the evaporator and is adapted to cause expansion and contraction of the bellows 73, to actuate the trip mechanism 71 in accordance with the temperature of the evaporator. The controller 72 also includes a thermostat device 77 located within the generator-absorber 20 and responsive to the temperature thereof and cooperates with the bellows for controlling the trip mechanism 71. The control of the gas for heating the generator-absorber and the flow of water for cooling the generator and the mechanism for operating the same is more fully described in the copending aplication of Harry B. Hull, Serial No. 48,280, filed August 5, 1925, and it is deemed that the foregoing description thereof is suflicient for the purposes of the present invention.

The heating of the absorbent and refrigerantwithin the generator-absorber will sometimes cause the absorbent to vaporize to a more or less degree; and, although a greater portion of the vaporized absorbent will be condensed within the dehydrator coils 22 and 23, a portion of the vaporized absorbent may pass into the condenser 22 where it will condense and fiow into the evaporator 31. If a large quantity of absorbent should be permitted to collect within the evaporator 31, the efficiency of the system would be impaired. Therefore, it is necessary that absorbent, which collects within the evaporator, should be delivered therefrom to the generator-absorber. In the present invention the evaporator 31 is provided with a brine tank portion 80 in which is immersed a conduit 81 extending fromione end of the evaporator downwardly and toward the other end of the evaporator where it connects with a conduit 82 extending from the evaporator 31. Absorbent will collect within the conduits 81 and 82. Pipe 83 is connected adjacent the bottom of the conduits 81 and 82 and has its other end connected with a chamber 84 of a valve 85. The valve 85 includes a second chamber 86 located below the chamber 84 and contains a relatively heavy liquid such as mercury 87.

A pipe 88 is connected with the chamber 84 and is immersed in the mercury 87. The outlet of the valve 85 is located above the mercury within the chamber 86. A conduit 88 is connected with the outlet of valve 85 and with a chamber 89 of a valve 90. Valve 90 also includes a chamber 91 which contains mercury 92 or the like and is located below the chamber 89. A pipe 93 connects with the chamber 89 and is immersed in the mercury 92. The outlet of the valve 90 is located above the mercury level and is connected with the chamber 48 of. the valve 35 by a pipe 94.

Considering that there is a quantity of absorbent within the conduits 81 and 82 of the evaporator 31, then when there is a predetermined pressure within the system, the absorbent will be forced upwardly through the pipe 83, through chamber 84, pipe 88 and into the chamber 86 of valve 85, conduit 88, chamber 89 of valve 90 and pipe 93 of valve 90. At this time the pressure within the pipe 94 and the pipe 83 will be substantially the same; and, since there is a pressure in the pipe 94 and likewise in the chamber 91 of valve 90 which is substantially equal to the pressure within the chamber 89 and conduit 88 and chamber 86, the absorbent will not flow from the chamber 89 into the chamber 91. However, when the pressure recedes within the system, due to the further cooling of the absorbent within the generator-absorber 20, the pressure within the pipe 94 and within the pipe 83 will recede substantially an equal degree, while the pressure within creases to such a degree that the pressure within the chamber 89, conduit 88 and chamber 86 can overcome the head of mercury within the pipe 93, the absorbent will be forced from the chamber 89 into the chamber 91, whence it passes into chamber 48 through pipe 94. After the absorbent enters the chamber 48 it will flow to the generator-absorber through the pipe 34 the same as the refrigerant flows therethrough.

The system as described provides for de' livering a certain amount 0. liquid from the evaporator to the generator at each cycle of refrigerating operation and if any absorbent should collect within the evaporator it will be forced during the succeeding cycle of refrigerating operation from the evaporator into the generator-absorber.

While the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood thatother forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. An absorption refrigerator system comprising, in combination, a container for re frigerant and absorbent, means for condensing vaporized refrigerant and for receiving the condensed refrigerant, a co duit operatively connecting the container and said means, and a conduit connecting the means with the container and having means for receiving absorbent from the first named. means and trapping said absorbent when a certain pressure is present in the system and for releasing said tra ped absorbent and conducting same into the container when the pressure within the system chan es, said last means including a plurality o non-return valves connected in series relation in said conduit.

2. An absorption refrigerator system comprising, in combination, a container for refrigerant and absorbent, means for condensing vaporized refrigerant and for receiving the condensed refri erant, a conduit operatively' connecting t e container and said means, and a conduit connecting the means with the container and having means for re- Kilt-l ceiving absorbent from the first named means and trapping said absorbent when a certain pressure is present in the system and for releasing said trapped absorbent and conducting same into the container when the pressure within the system changes, said last means including a plurality of non-return valves connected in series relation in said conduit and containing liquid for controlling the flow of absorbent therethrough.

An absorption refrigerator system comprising, in combination, a container for refrigerant and absorbent, means for condensing vaporized refrigerant and for receiving the condensed refrigerant, a conduit operatively connecting the container and said means, and means for receiving absorbent from the first named means and trapping said absorbent when a certain pressure is present in the system and for releasing said trapped absorbent and conducting same into the container when the pressure within the system changes, said last means including a chamber containing liquid, a conduit immersed in said liquid and connected with the first named means, and an outlet located above said liquid, said last means also including a non-return valve connected with said outlet, and a conduit connected with the outlet of the valve and said container.

4. An absorption refrigerator system comprising, in combination, a container for refrigerant and absorbent, means for condensing vaporized refrigerant and for receiving the condensed refrigerant, a conduit operatively connecting the container and said means, and means for receiving absorbent from the first named means and trapping said absorbent when a certain pressure is present in the system and for releasing said trapped absorbent and conducting same into the container when the pressure within the system changes, said last means including a non-return valve, a conduit connected with the inlet of said valve and with the first named means, said last means also including a chamber containing liquid and having its inlet below the level of the liquid therein and connected with the outlet of said valve and having an outlet above the liquid, and including a conduit connected with the outlet of said chamber and with the container.

' 5. An absorption refrigerator system comprising, in combination, a container for refrigerant and absorbent, means for condensing vaporized refrigerant and for rece1ving the condensed refrigerant, a conduit operatively connecting the container and said means, and means forreceiving absorbent from the first named means and trapping said absorbent when a certain pressure is present in the system and for releasing said trapped absorbent and conducting same into the container when the pressure Within the system changes, said last means including a signature.

ERNEST R. I. PRATT. 

